Increasing demand of whiteleg shrimp Litopenaeus vannamei promotes aquaculture businesses. However, sudden changes on environmental parameters such as salinity, pH and ammonia concentration can affect the survival of L. vannamei. Thus, this study aimed to determine the mortality of juvenile L. vannamei to sudden changes of various salinities, pH and ammonia concentrations and the median lethal concentration of those environmental parameters to juvenile L. vannamei. The tolerance of the juvenile was tested to different salinities (0 to 40.0 ppt), pH (pH 3.5 to 4.5) and total ammonia nitrogen (TAN) concentrations (0.02 to 200 mg/l). The juvenile showed mortality at 0 - 7.5 ppt with the highest mortality was recorded at 0 ppt. Meanwhile, they showed mortality at 60 - 200 mg/l TAN concentration, with the highest mortality was recorded at 100 mg/l and 200 mg/l. At pH test, the juvenile showed mortality at pH 3.5 - 4.5. The highest mortality was recorded at pH 3.5. The LC50 of salinity, TAN and pH on L. vannamei juvenile was at 3.53 ppt, 70.47 mg/l and pH 4.11. This study found that L. vannamei juveniles able to tolerate sudden changes in salinity (40 ppt to 2.5 ppt), ammonia (as high as 70 mg/l TAN) and pH (as low as pH 4). This study also found that these factors can affect the survival of juvenile without the manipulation of other factors. Thus, this information is important for proper pond management by providing baseline information and eventually minimizing the economic loss of the small-scale business.